The Use of Portable Computers: A Survey of Visually Impaired College Students

This survey of 10 visually impaired college students found that the students used portable (laptop) computers to produce assignments and to perform other tasks, as well as to take notes in class. The use of laptops seemed to foster the students’ independence and gave them sufficient time to complete their work.

Use of Noninvasive Ventilation with Volume-Assured Pressure Support in Neuralgic Amyotrophy with Bilateral Diaphragmatic Paralysis

Neuralgic Amyotrophy (NA) is a rare, acute onset inflammatory brachial plexopathy that frequently presents with acute pain followed by shoulder girdle muscle weakness. Phrenic nerve involvement affecting the diaphragms occurs in 7-10% of cases. We present the case of a 52-year-old man with neuralgic amyotrophy with phrenic nerve involvement and bilateral diaphragmatic paralysis with marked respiratory symptoms and sleep hypoventilation, who was treated with non-invasive ventilation with volume assured pressure support mode. By 21 months post disease onset, the patient had experienced marked improvement in orthopnea, sleep quality and functional status. This is the first reported case of the use of this mode of noninvasive ventilation in neuralgic amyotrophy.

Use of Noninvasive Ventilation with Volume-assured Pressure Support for Treatment-refractory Myasthenia Gravis

Background: Stepwise approach to therapy and increasing use of immunosuppressive agents have led to increasingly good prognosis and survival in myasthenia gravis (MG). However, there is a small subset of patients with treatment-refractory disease who experience a higher disease burden and increased rates of myasthenic crises and exacerbations, including respiratory failure. A 54-year-old man with treatment-refractory MG on chronic plasma exchange therapy had rapidly fluctuating weakness, poor sleep quality, and worsening respiratory symptoms in between treatments. He was started on home nocturnal noninvasive ventilation with volume-assured pressure support mode and experienced marked improvement in sleep quality, dyspnea, fatigue, and daytime sleepiness.

Rapidly progressive interstitial lung disease due to anti-melanoma differentiation associated protein-5 requiring a bilateral lung transplant, and complicated by kennel cough

The association between inflammatory myopathies anti-synthetase syndrome and interstitial lung disease has been recognized since the 1950s. Patients generally present with gradual onset of symptoms and slow progression of fibrosis over months to years. Herein, we describe a previously well 51-year-old man who presented with three months of progressive small joint arthritis, cough, dyspnea, and eventually hypoxemic respiratory failure following a viral prodrome. He continued to decompensate despite high dose corticosteroids and mycophenolate mofetil, ultimately requiring extracorporeal membranous oxygenation as a bridge to bilateral lung transplantation. Clinically amyopathic dermatomyositis (CADM) was confirmed through serum positivity for anti-Melanoma Differentiation Associated Protein-5 (MDA-5) antibody. Interestingly, his post-operative course was complicated by a zoonotic infection with Bordetella bronchiseptica. This case highlights the importance of identifying rare autoimmune diseases, and the utility of transfer to a lung transplant center.

Organizing pneumonia co-existing with carcinoid tumour: complete resolution with bronchoscopic tumour resection

Organizing pneumonia is a well-known clinical entity resulting in response to noxious stimuli causing lung injury. It is known to occur with infectious disease processes, neoplasms, post lung surgery or radiation therapy and when idiopathic, is called cryptogenic organizing pneumonia. We present an unusual case of a 48-year-old woman who presented with chronic cough and progressive dyspnoea while being on macrolide therapy for Lyme disease. Computerized tomography of chest demonstrated a well-circumscribed nodule in the lingula and bilateral central ground glass opacities. Transbronchial biopsies were consistent with carcinoid tumour in the lingula and organizing pneumonia in bilateral lung fields. Bronchoscopic relief of obstruction was performed by mechanical debulking of the tumour, with subsequent complete resolution of bilateral opacities, consistent with resolution of organizing pneumonia without the need for steroid therapy.

IFN-γ controls IL-33 protein level through a STAT1- and LMP2-dependent mechanism (CCR5P.268)

IL-33 levels and activity are differentially associated with Th1 and Th2 phenotypes. IL-33 mRNA is rapidly regulated but the fate of synthesized IL-33 protein is unknown. To assess the interplay between IL-33, IFN-γ, and IL-4 proteins, replication-deficient adenoviruses (AdV) were constructed for dual expression of IL-33 & IFN-γ or of IL-33 & IL-4. Combined IL-33 & IFN-γ or IL-33 & IL-4 effects were compared with similar AdV expression of each of these cytokines alone. Co-delivery of IL-33 & IFN-γ led to mutual suppression, and co-delivery of IL-33 & IL-4 led to mutual elevation of these proteins in cell culture and in vivo. Purified IFN-γ also attenuated IL-33 protein but not mRNA driven by the recombinant CMV promoter in AdV-IL-33-infected cells, suggesting that IFN-γ controls IL-33 protein degradation. Pharmacological inhibition, siRNA-mediated silencing, or gene deficiency of STAT1 potently upregulated IL-33 protein expression levels and attenuated the downregulating effect of IFN-γ on IL-33. Inhibition of caspase-1, -3, or -8 had minimal effect on IFN-γ-driven IL-33 protein downregulation. siRNA-mediated silencing of LMP2 proteasome subunit, which is known to be essential for IFN-γ-regulated antigen processing, also abrogated the effect of IFN-γ on IL-33. Thus, IL-33, IFN-γ, and IL-4 are engaged in a complex interplay, part of which involves IFN-γ-activated, caspase-independent, STAT1-mediated degradation of IL-33 protein through non-canonical use of LMP2 proteasome.

In vivo evaluation of a breast-specific magnetic resonance guided focused ultrasound system in a goat udder model

PURPOSE

This work further evaluates the functionality, efficacy, and safety of a new breast-specific magnetic resonance guided high intensity focused ultrasound (MRgFUS) system in an in vivo goat udder model.

METHODS

Eight female goats underwent an MRgFUS ablation procedure using the breast-specific MRgFUS system. Tissue classification was achieved through the 3D magnetic resonance imaging (MRI) acquisition of several contrasts (T1w, T2w, PDw, 3-point Dixon). The MRgFUS treatment was performed with a grid trajectory executed in one or two planes within the glandular tissue of the goat udder. Temperature was monitored using a 3D proton resonance frequency (PRF) MRI technique. Delayed contrast enhanced-MR images were acquired immediately and 14 days post MRgFUS treatment. A localized tissue excision was performed in one animal and histological analysis was performed. Animals were available for adoption at the conclusion of the study.

RESULTS

The breast-specific MRgFUS system was able to ablate regions ranging in size from 0.4 to 3.6 cm(3) in the goat udder model. Tissue damage was confirmed through the correlation of thermal dose measurements obtained with realtime 3D MR thermometry to delayed contrast enhanced-MR images immediately after the treatment and 14 days postablation. In general, lesions were longer in the ultrasound propagation direction, which is consistent with the dimensions of the ultrasound focal spot. Thermal dose volumes had better agreement with nonenhancing areas of the DCE-MRI images obtained 14 days after the MRgFUS treatment.

CONCLUSIONS

The system was able to successfully ablate lesions up to 3.6 cm(3). The thermal dose volume was found to correlate better with the 14-day postablation nonenhancing delayed contrast enhanced-MR image volumes. While the goat udder is not an ideal model for the human breast, this study has proven the feasibility of using this system on a wide variety of udder shapes and sizes, demonstrating the flexibility that would be required in order to treat human subjects.

Effects of MRTI sampling characteristics on estimation of HIFU SAR and tissue thermal diffusivity

While the non-invasive and three-dimensional nature of magnetic-resonance temperature imaging (MRTI) makes it a valuable tool for high-intensity focused ultrasound (HIFU) treatments, random and systematic errors in MRTI measurements may propagate into temperature-based parameter estimates used for pretreatment planning. This study assesses the MRTI effects of zero-mean Gaussian noise (SD = 0.0-2.0 °C), temporal sampling (tacq = 1.0-8.0 s), and spatial averaging (Res = 0.5-2.0 mm isotropic) on HIFU temperature measurements and temperature-based estimates of the amplitude and full width half maximum (FWHM) of the HIFU specific absorption rate and of tissue thermal diffusivity. The ultrasound beam used in simulations and ex vivo pork loin experiments has lateral and axial FWHM dimensions of 1.4 mm and 7.9 mm respectively. For spatial averaging simulations, beams with lateral FWHM varying from 1.2-2.2 mm are also assessed. Under noisy conditions, parameter estimates are improved by fitting to data from larger voxel regions. Varying the temporal sampling results in minimal changes in measured temperatures (<2% change) and parameter estimates (<5% change). For the HIFU beams studied, a spatial resolution of 1 × 1 × 3 mm(3) or smaller is required to keep errors in temperature and all estimated parameters less than 10%. By quantifying the errors associated with these sampling characteristics, this work provides researchers with appropriate MRTI conditions for obtaining estimates of parameters essential to pretreatment modeling of HIFU thermal therapies.

Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array

PURPOSE

This work presents the design and preliminary evaluation of a new laterally mounted phased-array MRI-guided high-intensity focused ultrasound (MRgHIFU) system with an integrated 11-channel phased-array radio frequency (RF) coil intended for breast cancer treatment. The design goals for the system included the ability to treat the majority of tumor locations, to increase the MR image's signal-to-noise ratio (SNR) throughout the treatment volume and to provide adequate comfort for the patient.

METHODS

In order to treat the majority of the breast volume, the device was designed such that the treated breast is suspended in a 17-cm diameter treatment cylinder. A laterally shooting 1-MHz, 256-element phased-array ultrasound transducer with flexible positioning is mounted outside the treatment cylinder. This configuration achieves a reduced water volume to minimize RF coil loading effects, to position the coils closer to the breast for increased signal sensitivity, and to reduce the MR image noise associated with using water as the coupling fluid. This design uses an 11-channel phased-array RF coil that is placed on the outer surface of the cylinder surrounding the breast. Mechanical positioning of the transducer and electronic steering of the focal spot enable placement of the ultrasound focus at arbitrary locations throughout the suspended breast. The treatment platform allows the patient to lie prone in a face-down position. The system was tested for comfort with 18 normal volunteers and SNR capabilities in one normal volunteer and for heating accuracy and stability in homogeneous phantom and inhomogeneous ex vivo porcine tissue.

RESULTS

There was a 61% increase in mean relative SNR achieved in a homogeneous phantom using the 11-channel RF coil when compared to using only a single-loop coil around the chest wall. The repeatability of the system's energy delivery in a single location was excellent, with less than 3% variability between repeated temperature measurements at the same location. The execution of a continuously sonicated, predefined 48-point, 8-min trajectory path resulted in an ablation volume of 8.17 cm(3), with one standard deviation of 0.35 cm(3) between inhomogeneous ex vivo tissue samples. Comfort testing resulted in negligible side effects for all volunteers.

CONCLUSIONS

The initial results suggest that this new device will potentially be suitable for MRgHIFU treatment in a wide range of breast sizes and tumor locations.

IL-33 precursor regulates inflammation in vivo in a T1/ST2-independent, Th2-independent fashion (P6270)

IL-33 precursor (IL33PR) released from damaged cells is known to bind to the receptor T1/ST2 and activate cells in culture. However, we found that in patients with interstitial lung diseases (ILD) and in the bleomycin mouse model of lung injury, pulmonary expression of IL33PR is elevated intracellularly and intranuclearly. Recombinant adenoviral gene delivery of IL33PR to mouse lungs in vivo did not lead to IL-33 maturation and produced a phenotype that was strikingly different from that induced by mature IL33 (MIL33). IL33PR induced pulmonary lymphocytosis and neutrophilia, whereas MIL33 induced eosinophilia, goblet cell hyperplasia, and increases in Th2 cytokines. The effects of MIL33 were, but the effects of IL33PR were not, abrogated by gene deficiency of T1/ST2. When combined with bleomycin injury, IL33PR potentiated lymphocytosis, collagen accumulation, and the expression of proinflammatory and profibrotic cytokines TGF-β, IL-6, MCP-1, and MIP-1α in the lungs. Gene expression profiling in cultured fibroblasts and epithelial cells overexpressing IL33PR revealed 10 - 100 fold increases in HSP70 mRNA, further confirmed by RT-Q-PCR. Previous reports have associated HSP70 with ILD. Immunohistochemical analyses showed strong HSP70 protein increases in mice challenged with bleomycin, IL33PR gene delivery, and particularly in mice challenged with these factors combined. Thus, IL33PR promotes ILD by inducing proinflammatory and profibrotic cytokines and HSP70.

An 11-channel radio frequency phased array coil for magnetic resonance guided high-intensity focused ultrasound of the breast

In this study, a radio frequency phased array coil was built to image the breast in conjunction with a magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) device designed specifically to treat the breast in a treatment cylinder with reduced water volume. The MRgHIFU breast coil was comprised of a 10-channel phased array coil placed around an MRgHIFU treatment cylinder where nearest-neighbor decoupling was achieved with capacitive decoupling in a shared leg. In addition a single loop coil was placed at the chest wall making a total of 11 channels. The radio frequency coil array design presented in this work was chosen based on ease of implementation, increased visualization into the treatment cylinder, image reconstruction speed, temporal resolution, and resulting signal-to-noise ratio profiles. This work presents a dedicated 11-channel coil for imaging of the breast tissue in the MRgHIFU setup without obstruction of the ultrasound beam and, specifically, compares its performance in signal-to-noise, overall imaging time, and temperature measurement accuracy to that of the standard single chest-loop coil typically used in breast MRgHIFU.

Interleukin-33 and its receptor ST2 contribute to inflammation in the lungs of patients with idiopathic pulmonary fibrosis (161.16)

Interleukin (IL)-33 and its receptor ST2 have been recently implicated as critical regulators of responses to injury and of ensuing inflammation. The roles of IL-33 and ST2 in pulmonary inflammation and scarring remain unclear. We analyzed bronchoalveolar lavage (BAL) from patients with idiopathic pulmonary fibrosis (IPF), a disease characterized by inflammation, with known elevated levels of IL-8 and excessive collagen deposition in the lungs. IL-33 was not found in BAL from 5 controls but was found in 7 out of 11 IPF samples, at 10.0 ± 3.2 pg/ml. Soluble ST2 was found in BAL from healthy controls at 93.2 ± 82.1 pg/ml, and in all IPF samples at 352.1 ± 135.2 pg/ml (p &lt; 0.05, Mann-Whitney U test). The elevation of IL-33 in BAL suggested that this cytokine may act directly on pulmonary epithelial cells and through this action contribute to inflammation. Cultured human primary pulmonary epithelial cells were stimulated with rhIL-33, and the levels of pro-inflammatory cytokines IL-6, IL-8, MIP-1α, and TNF-α in cell culture media were analyzed by ELISA. Of the analyzed cytokines, only the levels of IL-8 were increased by 2.0 ± 0.2 fold at 24 h and 1.7 ± 0.2 fold at 48 h. In conclusion, levels of IL-33 and ST2 are elevated in the lungs of IPF patients; IL-33 may contribute to inflammation and fibrosis by activating IL-8 production in pulmonary epithelium.

Inhaled cyclosporine and pulmonary function in lung transplant recipients

BACKGROUND

Chronic rejection, manifesting as bronchiolitis obliterans, is the leading cause of death in lung transplant recipients. In our previously reported double-blinded, placebo-controlled trial comparing inhaled cyclosporine (ACsA) to aerosol placebo, the rate of bronchiolitis-free survival improved. However, an independent analysis of pulmonary function, a secondary endpoint of the trial, was not performed. We sought to determine the effect of ACsA, in addition to systemic immunosuppression, on pulmonary function.

METHODS

From 1998-2001, 58 patients were randomly assigned to inhale either 300 mg of ACsA (28 patients) or placebo aerosol (30 patients) 3 days a week for the first 2 years after transplantation. Longitudinal changes in pulmonary function of ACsA patients were compared to aerosol placebo patients. In another analysis, the rate of decline from 6-month maximum FEV(1) in randomized patients was compared to the rate of decline in patients receiving conventional immunosuppression from the Novartis transplant database (644 patients, 12 centers worldwide, transplanted from 1990-1995).

RESULTS

The average duration of ACsA and aerosol placebo was 400 days +/- 306 and 433 +/- 256, respectively. The change in FEV(1) of ACsA patients (adjusted for Cytomegalovirus (CMV) mismatch and transplant type, followed for a maximum duration of 4.6 years) was superior to the aerosol placebo controls (9.0 +/- 71.4 mL/year vs. -107.9 +/- 55.3, p = 0.007). The FEF(25-75) decreased by -220.3 +/- 117.7 L/(second x year) vs. -412.2 +/- 139.2, p = 0.07, respectively. Similarly, percent FEV(1) decline from maximal values was improved in ACsA patients compared to aerosol placebo and Novartis controls (ACsA -0.43 +/- 1.12%/year vs. aerosol placebo -4.08 +/- 1.4, p = 0.04; ACsA vs. Novartis -4.7 +/- 0.31, p = 0.007). Single-lung recipients receiving ACsA showed improvement in FEV(1) compared to Novartis controls (FEV(1) -0.8 +/- 1.8%/year vs. -4.94 +/- 0.4, p = 0.03) but double-lung recipients showed improvement compared to aerosol placebo controls only (FEV(1) -0.28 +/- 1.22%/year vs. -8.53 +/- 5.95, p = 0.048).

CONCLUSIONS

In this single center trial, ACsA appears to ameliorate important pulmonary function parameters in lung transplant recipients compared to aerosol placebo and historical control patients. Single- and double-lung transplant recipients may not respond uniformly to treatment, and ongoing randomized trials in lung transplant recipients using ACsA may help elucidate our findings.

Alternatively spliced IL-4 protein is naturally secreted by T cells (51.2)

We have previously described an alternatively spliced isoform of IL-4 mRNA that omits exon 2 (IL-4δ2). We and others reported that the total levels of combined IL-4 + IL-4δ2 mRNAs and IL-4 / IL-4δ2 mRNA ratios change in patients with scleroderma, asthma, and various infections. Natural IL-4δ2 protein was not previously studied because most commercial anti-IL-4 antibodies (Ab) do not react with IL-4δ2. We established mammalian expression systems (HEK293 stably transfected or infected with recombinant adenoviral constructs) producing naturally processed (folded and glycosylated) human IL-4 or IL-4δ2. By screening a library of commercial anti-IL-4 Abs, we identified a selective Ab reacting exclusively with IL-4, and an indiscriminate Ab reacting equally with IL-4 and IL-4δ2. PBMC and T lymphocyte (&gt; 95% purity) cultures from 3 donors with allergic asthma and 3 controls were stimulated with PMA/ionomycin for 24 hrs. The supernates were immunodepleted of wild-type IL-4 using four cycles of depletion with the selective antibody. These immunodepleted supernates were negative in ELISAs with the selective anti-IL-4 Ab. However, the IL-4-depleted supernates from asthmatics, but not controls, were positive in ELISAs with the indiscriminate antibody that now detected only IL-4δ2. The levels of IL-4δ2 were 5 to 10 fold lower than the levels of IL-4 in the initial undepleted supernates. Thus, IL-4δ2 is naturally produced not only in the mRNA form, but also as a secreted protein.

Evidence for a behavioral significance of saccular acoustic sensitivity in humans

In this article the results are reported of an experiment to provide direct evidence for a perceptual and behavioral significance of human saccular acoustic sensitivity. Ten human subjects were stimulated monaurally with 100-ms trains of 10-ms tone pulses with pulse repetition rate of 40 Hz, and were required to rate the pleasantness of the stimuli on a nine-point scale. The design included three within-subject factors: carrier frequency (two levels, 200 and 4,000 Hz), intensity [13 levels from 55 to 115 dB(A) in 5-dB steps] and ear (left and right). For intensities above 90 dB myogenic vestibular evoked potentials (MVEP) were also obtained from the ipsilateral sternocleidomastoid muscle from which it was possible to obtain thresholds by linear regression of MVEP amplitudes against intensity. A further between-subjects factor was added which assessed subjects' attitude to vestibular sensations. The results indicate that across subjects there is a general trend of decreasing pleasantness with increasing intensity, but for the 200-Hz condition there is a significant positive departure from monotonicity in pleasantness (p<0.05) above the mean saccular threshold. However, when split by the between-subjects factor, the positive departure was only evident for those subjects who have a positive attitude to vestibular sensations (p < 0.01). Implications of these results for human responses to loud sound and the possible evolutionary significance of saccular acoustic sensitivity are discussed.

Acute bronchopulmonary infection due to Streptococcus milleri in a child with cystic fibrosis

An 8 year old girl with cystic fibrosis had severe respiratory disease associated with chronic Pseudomonas aeruginosa bronchopulmonary infection. Despite regular courses of intravenous antipseudomonal antibiotics, she continued to deteriorate over 18 months with persistent productive cough, worsening respiratory function, and increasing oxygen dependence. During her 11th admission Streptococcus milleri was isolated from sputum cultures in addition to P aeruginosa. She failed to respond to antipseudomonal antibiotics but improved dramatically with the addition of intravenous benzylpenicillin. Although S milleri is considered a normal mouth commensal and its isolation from sputum of cystic fibrosis patients is of uncertain significance, it was associated with clinically significant infection in this child. S milleri was eradicated with antibiotic treatment and clinical improvement has been maintained.

The physiological knowledge required by nurses caring for patients with unstable angina

Physiological knowledge necessary to critically analyse nursing management of patients with unstable angina is reviewed. The role of endothelium derived relaxing factor, nitrous oxide and atherosclerosis is summarised. The effects of circadian rhythms or clinical signs and symptoms in patients with unstable angina is particularly highlighted. Pharmacological interventions are considered from the perspective of implications for nursing care and other important nursing interventions identified for coronary care nurses.

Pineal tumours in the north of England 1968-93

The records of 38 patients under 25 years of age presenting with pineal tumours between 1968 and 1993, identified from the Northern Region Children's and Young Adults' Malignant Disease Registry, were analysed retrospectively with regards to clinical presentation, diagnostic approach, treatment strategy, and outcome. The overall five year survival was 45%. Fifteen patients had a histological diagnosis: six with germinomas, three with teratomas, three with astrocytomas, and three with pinealoblastomas. One patient had a definitive diagnosis of teratoma made on the basis of raised tumour markers (alpha fetoprotein). Treatment consisted of surgery (87%) (ventriculoperitoneal or atrial shunt and/or biopsy), and/or radiotherapy (82%), and/or chemotherapy (26%). Those patients with a tissue diagnosis appeared to have a more favourable outcome, especially after 1976 when treatment was determined by tumour type (five year survival for those with a tissue diagnosis was 91% v 51% for those without, 95% confidence intervals 74 to 100% and 26 to 75%). This study suggests that tissue diagnosis allows more appropriate treatment to be delivered for children with pineal tumours resulting in improved survival. Referral to a centre with neurosurgery, radiotherapy, neuropathology, and paediatric oncology collaboration is essential.

A new selective differential medium for isolation of Stenotrophomonas maltophilia

A new selective differential medium for the isolation of Stenotrophomonas (formerly Xanthomonas) maltophilia was developed. The medium, VIA agar, contained vancomycin, imipenem, and amphotericin B as selective agents and incorporated a mannitol/bromothymol blue indicator system. Compared with Xanthomonas maltophilia Selective Medium (XMSM), VIA agar was less inhibitory to Stenotrophomonas maltophilia and was more selective than XMSM in preventing the growth of unwanted bacteria from contaminated specimens. Although vancomycin-resistant strains of Enterococcus faecium may grow on VIA agar, these can be easily distinguished from Stenotrophomonas maltophilia because of mannitol fermentation.

An auditory cortical theory of primitive auditory grouping

Auditory stream segregation is considered from the point of view of a theory of the central auditory system in which temporal information is spatially coded on three dimensions roughly corresponding to the level of the cochlea, the inferior colliculus and the auditory cortex, respectively. This theory is embodied in the form of a computational model which simulates peripheral and central processing including a cortical cross-channel correlation mechanism.

Molecular epidemiology of ceftazidime resistant Enterobacteriaceae from patients on a paediatric oncology ward

Between the autumn of 1989 and January 1990, 21 of the 44 children on the paediatric oncology ward of St. James's University Hospital, Leeds, UK were infected or colonised with Enterobacteriaceae producing extended-spectrum beta-lactamases. This represents 48% of the patients on the ward. Only six patients (14%) had microbiologically proven septicaemia caused by such bacteria during this period. Eighty-one isolates of Enterobacteriaceae producing extended-spectrum beta-lactamases derived from blood culture (7 isolates from 6 patients) or faecal samples (74 isolates) were available for examination. These comprised 28 Escherichia coli, 28 Klebsiella oxytoca, 11 Klebsiella pneumoniae, 10 Citrobacter freundii, 3 Enterobacter spp. and 1 Serratia marcescens. Clinical isolates were resistant to penicillins and to ceftazidime. Strains isolated in this study also showed multiple resistance to a range of antimicrobial agents. Transfer to a nalidixic acid resistant laboratory strain of E. coli UB5201 was attempted, but transfer of the ceftazidime resistance determinant was only successful in 25 isolates (31%). Examination of plasmid DNA revealed sequences in each isolate that hybridised with the TEM beta-lactamase gene probe used on a variety of plasmids ranging in size from 2.5- > 150 kb, sometimes found on several replicons in a single isolate. The TEM gene probe also hybridised with chromosomal DNA in a large number of isolates. Nucleotide sequence analysis demonstrated the presence of three extended-spectrum beta-lactamases: TEM-10B produced by two isolates, TEM-12B produced by 37 isolates and TEM-26B produced by 40 isolates. In two cases, isolates produced two beta-lactamases, and it proved impossible to identify these enzymes unequivocally. The genes encoding TEM-10B and TEM-26B both differ from TEM-12B by single nucleotide substitutions. Analysis of the ribotype patterns derived from the clinical isolates provided evidence for cross-colonisation between patients, and this was confirmed by analysis of the plasmid profiles. Four years after discontinuing ceftazidime and other extended-spectrum cephalosporins on this ward, patients were still colonised with bacteria that produced extended-spectrum beta-lactamases.

A comparison of molecular clearance rates during continuous hemofiltration and hemodialysis with a novel volumetric continuous renal replacement system

We developed a continuous, volumetrically controlled veno-venous renal replacement system that can be operated in filtration or dialysis modes. We compared the clearances of substances with a range of molecular weights (MW) in each mode. Ten patients with acute renal failure underwent serial postdilutional hemofiltration and hemodialysis, for 30 min each, in sequence and in randomized order. All were receiving vancomycin for concurrent sepsis. The system incorporated a Filtral 10 AN69 artificial kidney; blood flow rate was 200 ml/min, and dialysate/filtrate flow rate was 25 ml/min. Sieving (SC) and diffusion (DC) co-efficients, for hemofiltration and hemodialysis, respectively, were identical for urea (MW 60; 1.01 +/- 0.05 vs 1.01 +/- 0.07) and creatinine (MW 113; 1.00 +/- 0.09 vs 1.01 +/- 0.06), and clearance equated with dialysate/filtrate flow. There was a modest difference in uric acid clearance (MW 168; SC 1.01 +/- 0.04 vs DC 0.97 +/- 0.04; p < 0.05). Vancomycin (MW 1,800) removal was 19% greater during filtration compared with dialysis (SC 0.87 +/- 0.10 vs DC 0.74 +/- 0.06; p < 0.01). For small solutes, the two modalities were equivalent. Vancomycin clearance was appreciably greater with hemofiltration, which is consistent with a greater potential for convection-based therapy in the removal of uremic and other middle molecules.

Convergent evolution of TEM-26, a beta-lactamase with extended-spectrum activity

TEM-26, an extended-spectrum beta-lactamase has been characterized in clinical isolates of Klebsiella pneumoniae and Escherichia coli derived from patients on the Paediatric Oncology Unit of St James's University Hospital, Leeds. The nucleotide sequence of this beta-lactamase gene (blaTEM26b) was determined, and compared with the nucleotide sequences of other TEM-type beta-lactamases. The blaTEM26b gene was found to differ from blaTEM12b by a single nucleotide. This difference causes the substitution of glutamic acid in blaTEM12b for lysine in blaTEM26b at position 102 in the predicted amino acid sequence. The blaTEM12b gene was first described in an isolate of Klebsiella oxytoca from a patient nursed on the same unit that yielded the strains that carry blaTEM26b. However, the blaTEM26b gene differs at no less than six nucleotides from the nucleotide sequence encoding the TEM-26 beta-lactamase that was first described in isolates from cancer patients nursed in the Children's Hospital, Stanford, California, USA. This indicates that the genes encoding TEM-26 have evolved from different progenitors.

Transposition of the gene encoding a TEM-12 extended-spectrum beta-lactamase

An isolate of Klebsiella oxytoca from the blood culture of a child with leukemia was found to produce two beta-lactamases, at least one of which conferred resistance to ceftazidime. Genes encoding both enzymes were located on a single self-transmissible 100-kb plasmid, pOZ201. This plasmid was introduced into Escherichia coli UB5201 (pACYC184), and the gene encoding one beta-lactamase was transposed onto plasmid pACYC184 by exploiting a gene dosage effect. The transposable gene was found to encode a TEM-12 enzyme as determined by nucleotide sequencing. This gene was subsequently transposed onto plasmid pUB307. The transposable element encoding the TEM-12 enzyme has been designated Tn841. Both plasmids pACYC184::Tn841 and pUB307::Tn841 were shown to encode a beta-lactamase with the same isoelectric point and substrate profile as the TEM-12 beta-lactamase. Transposon Tn841, at approximately 7 kb, is larger than TnA (4.8 kb) and transposes at a lower frequency. Although it produced a resolvase which can complement the resolvase of Tn3, its transposase function was not able to complement the transposition of a TnA element which lacked transposase. The occurrence of a gene encoding an extended-spectrum beta-lactamase on a transposable element in a clinically significant bacterium is potentially a cause for concern for the spread of resistance to the extended-spectrum cephalosporins.

The epidemiology of Salmonella in calves: the role of markets and vehicles

Environmental contamination has been shown to be an important aspect of the epidemiology of salmonellosis in calves. Markets and transport vehicles are important links in the calf marketing chain and these were investigated to determine the level of salmonella contamination. Salmonellas were isolated from 7 of the 14 markets surveyed, with 31 of 838 samples (3.7%) being positive. Nine different salmonella serotypes, of which the commonest was Salmonella typhimurium, were isolated. Four different phage types of S. typhimurium were detected, the commonest being DT204C. Salmonellas were isolated from 22 of the 107 vehicles (20.6%) examined before washing and from 4 of the 62 vehicles (6.5%) examined after cleaning. Twelve different salmonella serotypes were isolated, of which the most frequent was S. typhimurium. The commonest of the six different S. typhimurium phage types was DT204C. These results indicate that improved cleaning and disinfection routines both for vehicles and markets are necessary to control salmonellosis in calves.

Epilepsy and the blood-brain barrier

Epilepsy is a common condition which is often resistant to therapy and may cause neurological damage. It is postulated that changes in blood-brain barrier function may be involved in the pathophysiology of both problems.

The epidemiology of Salmonella infection of calves: the role of dealers

Salmonellas were detected in the environment of 10 of the 12 calf dealers' premises studied. The cleaning and disinfection routines were often ineffective and salmonellas were isolated from 7.6% and 5.3% of the wall and floor samples before disinfection and 6.8% and 7.6% afterwards. Eight different salmonella serotypes were detected, of which the commonest were Salmonella typhimurium, predominantly phage type DT204C, and S. dublin. Plasmid profiles were used to fingerprint S. typhimurium DT204C and the results indicated that with the exception of one of the premises, prolonged salmonella-persistence in the environment was not occurring. Three separate epidemics of salmonellosis in calves were studied by use of plasmid profile analysis. The results illustrated the role of delers, and their subcontractors, in the dissemination of salmonellas. The study concludes with suggestions for methods to reduce the spread of salmonellas in the calf marketing chain.

A double-blind comparative study of remoxipride and thioridazine in the acute phase of schizophrenia

Sixty-one patients with acute schizophrenia received either remoxipride (75-375 mg daily) or thioridazine (150-750 mg daily) for 6 weeks. There was no statistically significant between-drug difference in improvement in mental state, as measured by the Brief Psychiatric Rating Scale, although the trend favoured thioridazine; global assessment of illness severity at the last rating also favoured thioridazine. Sedation, anticholinergic effects, autonomic dysfunction, and weight gain were significantly more common in patients receiving thioridazine. Both drugs produced few extrapyramidal effects, but both were associated with cardiovascular changes in two patients; neither drug produced significant abnormalities in laboratory tests.

Direct isolation of coagulase-negative staphylococci from neonatal blood samples

Coagulase-negative staphylococci (CNS) were isolated by direct inoculation of anticoagulated whole blood onto agar from 14 (41.2%) of 34 episodes (30 neonates) of suspected bacterial infection, associated with isolation of CNS from the same blood sample by broth-dilution blood cultures. The equivalent of more than 1,000 cfu ml-1 were isolated from four samples (four neonates); the range of counts was 1-103 cfu 25 microliters-1. There was a statistically significant association between isolation of CNS by direct agar inoculation and a raised C-reactive protein level and/or a positive nitroblue tetrazolium test and with the use of an intravascular catheter when compared to those episodes where CNS were isolated from broth blood cultures only. This simple procedure provides an estimate of the number of CNS in the blood of a neonate with suspected bacteraemia and may help to corroborate a diagnosis of CNS bacteraemia.

Aerosol infection of calves and mice with Salmonella typhimurium

The likelihood of airborne spread and infection by Salmonella typhimurium was studied in calves and mice. S typhimurium survived in air sufficiently long to present a significant hazard of airborne spread. In a dry climate (32 per cent relative humidity) its predicted viability five minutes after aerosolization was 4 per cent relative to its initial value. This increased to 24.8 per cent in a humid atmosphere (72 per cent relative humidity). Inhalation of S typhimurium by mice caused disease and death at times dependent upon the dose. Even the lowest dose of about 150 colony forming units (cfu) produced disease. Inoculation of approximately 10(4) to 10(6) cfu S typhimurium by either 'mouth and nose only' or 'whole body' aerosol exposure caused infection in calves. The consequences for the control of salmonellosis in intensive calf husbandry are discussed in the light of this demonstration that airborne transmission can be a primary mode of infection of S typhimurium.

A double blind comparative study of remoxipride and thioridazine in the acute phase of schizophrenia

This is the first comparative double blind study of remoxipride. Sixty-one patients with acute schizophrenia received either remoxipride (75-375 mg daily) or thioridazine (150-750 mg daily) for 6 weeks. There was no statistically significant between-drug difference in improvement in mental state, as measured by the Brief Psychiatric Rating Scale, although the trend favoured thioridazine; global assessment of illness severity at the last rating also favoured thioridazine. Sedation, anticholinergic effects, autonomic dysfunction and weight gain were significantly more common in patients receiving thioridazine. Both drugs produced few extrapyramidal effects, but both produced cardiovascular changes in two patients; neither drug produced significant abnormalities in laboratory tests.

Toxicity and mutagenicity of 6 anti-cancer drugs in Chinese hamster V79 cells co-cultured with rat hepatocytes

Toxicity and induction of 6-thioguanine-resistant mutants in Chinese hamster V79 cells, co-cultured with or without isolated rate hepatocytes, by 6 anti-cancer drugs (cyclophosphamide, adriamycin, methotrexate, cytosine arabinoside, 6-mercaptopurine and vincristine) were studied. The effect of hepatocyte density on the cloning efficiency and recovery of mutants was found using dimethylnitrosamine as a positive control. In the absence of hepatocytes, this compound was neither toxic nor mutagenic to V79 cells, but in their presence it was highly mutagenic and extremely toxic. The cloning efficiency and mutation frequency of control (untreated) cells was unaffected by hepatocyte density. All the drugs were toxic to V79 cells, although different responses were found for certain of them depending upon whether hepatocytes were present or not. Cyclophosphamide and adriamycin were clearly mutagenic, and 6-mercaptopurine only weakly so. A slight mutagenic effect was seen for cytosine arabinoside, but both methotrexate and vincristine were negative. Here also, the presence or absence of hepatocytes was important.

Presence of neuropeptide Y in human circle of Willis and its possible role in cerebral vasospasm

Neuropeptide Y (NPY) has been demonstrated in the human circle of Willis by specific radioimmunoassay. Concentrations were similar in cadaver and peroperative specimens. NPY concentrations were highest around the basilar bifurcation (2.9 +/- 1.0 pmol/g), anterior cerebral artery (2.7 +/- 0.5 pmol/g), and carotid trifurcation (2.4 +/- 0.6 pmol/g). Concentrations were lowest in the basilar artery (1.0 +/- 0.4 pmol/g). Intracarotid administration of NPY (50 pmol to 2 nmol) to rats reduced mean cerebral cortical blood flow by 40-98%. This vasoconstriction lasted for at least 2 h. These findings suggest that NPY may be involved in the cerebral vasospasm which follows subarachnoid haemorrhage and in the maintenance of normal vascular tone.

Bacteriology and treatment of purulent nasopharyngitis: a double blind, placebo-controlled evaluation

One hundred forty-two children with purulent nasopharyngitis were randomized to four treatment groups with an antibiotic (cephalexin) alone or combined with a decongestant/antihistamine (pseudoephedrine/triprolidine) or their corresponding placebo equivalents. Follow-up evaluations by parents and physicians and bacteriologic evaluations were performed after 5 to 6 days of therapy. Groups were comparable with regard to age, sex, race, number of patients withdrawn from the study, fever greater than 38.0 degrees C, appearance of nasal discharge, nasal crusting and number of days until follow-up. Initial cultures from patients grew: Streptococcus pneumoniae, 46%; Haemophilus influenzae type b, 21%; and Streptococcus pyogenes, 8%. Nasal crusting was significantly associated with the growth of S. pneumoniae or H. influenzae type b. There were no significant differences between active drug and placebo treatment groups for change in nasal discharge, complications or apparent drug benefit. Cephalexin therapy did not result in a decrease in cultivation of pathogenic organisms from the nasopharynx. Significantly more side effects were attributed to pseudoephedrine/triprolidine treatment than to placebo. Routine culture or treatment of purulent nasopharyngitis should not be considered unless future controlled clinical trials demonstrate some therapeutic benefit.